Issue 53

K. Afaf et alii, Frattura ed Integrità Strutturale, 53 (2020) 66-80; DOI: 10.3221/IGF-ESIS.53.06

a greater degradation of mechanical characteristics. The breaking of the macromolecular chain is responsible for the deterioration of PMMA properties; For longer ultraviolet radiation exposure times (beyond thirty-six months), the linear mechanical behavior of the non- irradiated PMMA changes to a non-linear behavior, with greater deformations as compared to the non-irradiated polymer; The modulus of Young of the PMMA drops sharply during the first six months of exposure to artificial (UV) lamp radiation then starts decreasing slowly during the following six months. It is important to precise that the degradation of this physical parameter is significantly slowed down during the last twenty-four months of aging. A similar behavior is observed during exposure to solar (UV) radiation but with lower values, regardless of the aging time. [1] Kowalonek, J., Kaczmarek, H., Kurzawa, M. (2016). Effect of UV-irradiation on fluorescence of poly (methyl methacrylate) films with photosensitive organic compounds, Journal of Photochemistry and Photobiology A: Chemistry. 319-320, pp.18-24. DOI: 10.1016/j.jphotochem.2015.12.017 [2] Münker, T.J.A.G., Van de Vijfeijken, S.E.C.M., Mulder, C.S., Vespasiano, V., Becking, A.G., Kleverlaan, C.J., and al. (2018). Effects of sterilization on the mechanical properties of poly(methyl methacrylate) based personalized medical devices, Journal of the Mecchanical Behavior of Biomedical Materials. 81, pp.168-172. DOI: 10.1016/j.jmbbm.2018.01.033. [3] Manjunatha, H.C. (2017). A study of gamma attenuation parameters in poly methyl methacrylate and Kapton, Journal of Radiation Physics and Chemistry. 137, pp. 254-259. DOI: 10.1016/j.radphyschem.2016.01.024 [4] Zhong, Z.W., Wang, Z.F., Zirajutheen, B.M.P.( 2005). Chemical mechanical polishing of polycarbonate and poly methyl methacrylate substrates, Journal of Microelectronic Engineering. 81, pp. 117-124. DOI: 10.1016/j.mee.2005.04.005. [5] Bussi, Y., Golan, S., Dosoretz, CG., Eisen, MS. (2018). Synthesis, characterization and performance of polystyrene/PMMA blend membranes for potential water treatment, Journal of Desalination. 431, pp.35-46. DOI: 10.1016/j.desal.2017.12.024. [6] Ali, U., Karim, K.J.B.A., Buang, N.A. (2015). A review of the properties and applications of poly (methyl methacrylate) (PMMA), Journal of Polymer Reviews. 55, pp.678-705. DOI.org/10.1080/15583724.2015.1031377. [7] Wenhua, Y., Zeyu, X., Yuming, Y., Jun, Y., Xiaodan, L., Huiqin, W., Shuang, W., Yufang, X., Yunong, Y. (2019). Aging behavior and lifetime prediction of PMMA under tensile stress and liquid scintillator conditions, Journal: Advanced Industrial and Engineering Polymer Research. DOI: 10.1016/j.aiepr.2019.04.002. [8] Bokoi, Y., Ishiyama, C., Shimojo, M., Shiraishi, Y., Higo, Y. (2000). Effects of sorbed water on crack propagation in poly(methyl methacrylate) under static tensile stress, Journal of Materials Science. 35, pp.5001-5011. DOI: https://doi.org/10.1023/A:1004803030131 [9] Ehsan, M., Reid, B., Hung, J.S. (2014). The effect of moisture exposure on scratch resistance of PMMA, Journal of Tribology International. 69, pp.46–55. DOI: 10.1016/j.triboint.2013.08. [10] Shen, J., Chen, C., Sauer, J. (1985). Effects of sorbed water on properties of low and high molecular weight PMMA: 1. Deformation and fracture behaviour, Journal of Polymer. 26, pp.511-518. DOI: 10.1016/0032-3861(85)90150-8. [11] Miller, D.C., Carloni, J.D., Johnson, D.K., Pankow, J.W., Gjersing, E.L., et al. (20.13). An investigation of the changes in poly (methyl methacrylate) specimens after exposure to ultra-violet light, heat, and humidity, Solar Energy, Journal of Materials and Solar Cells. 111, pp.165-180. [12] Fu, Y., Hsiao, S., Hu, C., Lee, K., Lai, J. (2008). Prediction of long-term physical aging of poly(methyl methacrylate) membranes for gas separation, Journal of Desalination. 234, pp.51-57. DOI: 10.1016/j.desal.2007.09.069. [13] Cheng, Q., Jiang, C., Zhang, J., Yang, Z., Zhu, Z., Jiang, H. (2016). Effect of thermal aging on the scratch behavior of poly (methyl methacrylate), Journal of Tribology International. 101: 110-114. DOI: 10.1016/j.triboint.2016.04.013 [14] Thominette, F., Verdu, J. (1996). Effect of a tensile stress on the radiolytic degradation of poly (methyl methacrylate), Journal of Polymer. 37, pp.1323-1327. DOI: 10.1016/0032-3861(96)81128-1 [15] Monsores, K. G. C., da Silva, A. O., de Sant’Ana Oliveira, S., Rodrigues, J. G. P., Pondé Weber, R. (2019). Influence of ultraviolet radiation on polymethylmethacrylate (PMMA), Journal of Materials Research and Technology, 8, pp. 3713-3718. DOI: 10.1016/j.jmrt.2019.06.023. [16] N’Diaye, M., Pascaretti-Grizon, F., Massin, P., Baslé, M. F., Chappard, D. (2012). Water Absorption of Poly (methyl methacrylate) Measured by Vertical Interference Microscopy, GEROM Groupe Etudes Remodelage Osseux et R EFERENCES

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